US citizens watch the live telecast of the 2016 US presidential elections on television at the US ambassador’s residence in Baghdad, Iraq, on Wednesday.
Photograph: Hadi Mizban/EPA

Donald Trump has been short on policy details during his campaign. But already, the president-elect has hinted at an agenda that is as ambitious as it is disturbing on key policy issues. Here’s what he will inherit and how he might respond, from the Guardian’s specialists.

Immigration

Trump will enter the White House riding a wave of xenophobia and fear driven in no small part by his plans to drastically overhaul America’s immigration system. The president-elect has pledged to implement many tenets of his controversial reform package from day one and will now be emboldened by a Republican majority in both houses of Congress. Meanwhile, countless immigrant communities across America will no doubt be terrified about just how far he might go.

Trump’s promise to build an “impenetrable physical wall” across the US southern border will supposedly commence on his first day in office. But the kicker to his now infamous campaign slogan – making “Mexico pay for it” – will prove a near impossible deal to broker as experts predict the cost of such a construction could be four times higher ($40bn) than Trump estimated during the campaign. Aside from the economics, the humanitarian consequences of increasing border security as hundreds of thousands of Central American migrants continue to flee violence at home and seek refuge in the US are near unfathomable.

Trump’s administration has pledged to pursue a temporary ban on migration from regions he deems exporters of terrorism and where even his “extreme vetting” will not be sufficient. Although this policy has gone through many iterations, the legality of such a program will almost certainly be challenged in the courts by those who argue it will simply act as a smokescreen to allow discrimination against Muslims seeking to enter America. Nonetheless, Trump is likely to be buoyed by the assistance of Congress.

For the 11 million undocumented immigrants living in the US, Trump’s presidency will usher in an era of heightened uncertainty and paranoia, as the president-elect has pledged to ramp up deportations. Trump will triple the number of Immigration and Customs Enforcement agents and seek to create a “special deportation taskforce”. Although the president-elect has claimed this taskforce will first focus on “the most dangerous criminal illegal immigrants”, Trump has made clear that any undocumented migrants could be affected. Up to 6.5 million people could be at risk of swift deportation.

The key question for the new administration will be at what point, if any, can it satisfy the demands of its white, conservative base, whipped up by the rhetoric of the campaign.

National security

Trump now has control over the vast US security apparatus, with all its power to kill, surveil and influence. Trump, whose command of policy specifics is minimal, has made no secret of his inclination to unleash it. Now he faces early tests of how far he will go.

Barack Obama will leave office with Guantánamo Bay still in operation as a detention facility. Trump’s election ensures the infamous wartime prison escapes closure, but it will probably cross a constitutional Rubicon. The president-elect has pledged to increase the Guantánamo population, a reversal of Obama’s approach, “with some bad dudes”. Among those “bad dudes”, Trump told the Miami Herald, could be American citizens. His pledge to bring back “worse than waterboarding” threatens to undo the shaky coalition against torture, especially in a GOP Congress, of the late Bush and Obama administrations.

The move would be illegal if Trump meant to try Americans in military commissions, and almost sure to be found unconstitutional if Trump meant holding Americans in indefinite detention. In the same interview, Trump also signaled a departure from both Obama and George W Bush in expressing opposition to using the criminal justice system for terrorism cases.

Since Trump’s definition of the domestic threat has centered on what he has called “radical Islamic terror”, US Muslim communities, already the target of widespread law-enforcement suspicion since 9/11, would probably find themselves subject to a separate system of wartime justice in which they would enjoy fewer rights.

Trump has unapologetically embraced “profiling” as a “commonsense” approach to predicting terrorist threats, by which he means increasing police and intelligence scrutiny of Muslim communities. Trump has endorsed surveillance in mosques and even a database of American Muslims, incendiary proposals that threaten traditional American liberties. The response of the FBI’s leadership – which already has a strong base of support for Trump and a history of teaching its agents to consider Islam itself a danger – will be a pivotal test for justice in the Trump era. So will his choice of intelligence agency leaders, as Trump has attracted little support among experienced intelligence officials outside of the far-right fringe.

Another immediate test Trump faces will be a military challenge. Obama will leave 8,400 US troops in Afghanistan. The fortunes of America’s longest war are on a downward trajectory as the Taliban reconquers lost terrain. Trump, who has criticized a withdrawal in Iraq he once supported as a gift to Islamic State, must now choose departure, failure or escalation.

Foreign policy

Trump spent the campaign threatening to upend what has been called the liberal international order, the network of treaties and multilateral institutions that govern global relations. He has said he would tear up and renegotiate trade treaties, and has even called into question US commitment to the Nato alliance, the linchpin of western cohesion. With a completely new kind of leader preparing to enter the Oval Office, it is already looking like a world turned upside down.

The long-negotiated multilateral trade deals the Trans-Pacific Partnership (TPP) and the Transatlantic Trade and Investment Partnership with Europe (TTIP) will be the first to be halted. Opposition to those accords was a cornerstone of the Trump campaign. Trump has also said he would take apart the 1994 North American Free Trade Agreement (Nafta) that binds the US economically it to its neighbors, Canada and Mexico.

In place of such treaties, he has said he would negotiate bilateral deals that would be more favorable for US manufacturing. But he would face hostile trading partners, irritated at the dumping of major agreements. Trump’s America could easily face a trade backlash and a downward economic spiral.

The other consistent theme of the Trump campaign was a foreign policy that revolved around his personality. He would bring his self-vaunted skills as a businessman to cut bilateral deals with other world leaders, particularly the autocrats.

Trump said he would even talk to Kim Jong-un if the North Korean dictator would travel to the US for the conversation. That is unlikely, but the prospect of an unconditional dialogue between leaders would throw a wild card into a deadlocked and extremely dangerous situation in which Pyongyang is well on the way to developing a nuclear warhead small enough to put on a missile, and a missile able to reach the west coast of the United States.

The relationship that will define the Trump presidency, however, will be with Vladimir Putin. Each of them has showered the other with praise. At every turn in the campaign, Trump refused to criticize Russian expansionist foreign policy in Ukraine and Syria. His aides specifically removed language from the Republican party platform about sending lethal aid to Ukraine, and Trump himself has echoed Putin’s denials of Russian military presence in the country’s east. In Syria, he has characterised the Russian and Assad regime bombardment of the opposition as a war on Islamic extremism, again emulating Moscow’s line.

Trump’s twin policies on the Islamic State (Isis) were to “take their oil” and “bomb the shit out of them”. The first is impractical without a vast military occupation and the second is illegal if it was suggesting indiscriminate bombing. A dual offensive against Isis is under way aimed at its twin strongholds of Raqqa and Mosul led by US allies, and a President Trump would face serious resistance from the Pentagon if he wanted to put US boots on the ground or carry out joint operations with the Russians.

Early on in a Trump presidency, expect a summit with Putin in which US-Russian relations will be reworked along lines the Russian leader has been pushing for, ceding Moscow areas of influence in the Middle East and on Russian borderlands.

Such a discussion will shock major US allies in Nato, an alliance Trump has described as “obsolete”. He has questioned whether it would be worthwhile for the US to provide a security umbrella to allies who are not deemed to have contributed enough, in financial terms, to collective security. Turmoil within Nato could meanwhile tempt Putin to make encroachments on its eastern flank. Few are more worried about the global consequences of a Trump win than the residents of Estonia, Latvia and Lithuania.

Healthcare

The one constant in Trump’s scattershot health policy is his promise to immediately repeal Obamacare. Just last week, Trump said that if elected he would convene a special congressional session to destroy the 2009 healthcare reform.

If he successfully repeals the law, which is unlikely, it would disproportionately affect low-income people, according to multiple analyses. The number of uninsured individuals would increase by 16m to 25m, according to the Commonwealth Fund, a research group. It would also increase the federal deficit, according to the same analysis, because the end of Obamacare means the end of taxes the health reform law brings in – adding about $33bn more to the deficit in the first year.

There is also the question of what replaces Obamacare. The closest thing the Republicans have to a substitute is a blueprint created by the House speaker, Paul Ryan, who has a rocky relationship with the president-elect.

For these reasons and more, it is unlikely Trump would get the congressional approval needed to actually repeal the law, though he and the Republican-dominated Congress could tear away at some of its key provisions. The rest of his health proposals are similarly chaotic.

Trump’s seven-point plan for healthcare includes allowing people to purchase insurance across state lines (allowing for greater variation in insurance regulations), deduct health insurance premiums from their tax returns and use health savings accounts.

He also aims to require price transparency from healthcare providers, allow more drugs to be imported from overseas and give block grants for Medicaid to states. And his plan would reduce access to abortion, contraception and preventative care.

Trump’s ideas “bewilder” establishment GOP health experts such as Robert Laszewski, who told the New York Times in April that the proposals were “a jumbled hodgepodge of old Republican ideas, randomly selected, that don’t fit together”.

Women and gender rights

Trump enters office with a lot of question marks hanging over his proposals on issues of gender. Will he support a childcare policy that doesn’t leave low-income families out in the cold? Would he continue to enforce the Obama administration’s executive actions on campus sexual assault? Would he preserve executive orders that protect transgender individuals from discrimination?

Trump hasn’t answered these questions, but if he follows the lead of the rest of the Republican party, the answer is probably a big “no”. Throughout the election, on issues of major cultural significance, Trump has tacked further and further to the right. After starting his campaign by suggesting that he was open to funding Planned Parenthood, for instance, and that Roe v Wade was settled law, he has come to fully embrace the Republican party line. Supreme court justices? They should be pro-life. Planned Parenthood? He’ll defund it. Trump also opposes the use of Medicaid to cover abortions for low-income women, and with a Republican Congress, he is willing to make that a matter of law.

Trump’s journey to the right is by no means limited to abortion rights. Earlier this year, Trump said he had no problem with trans people using the bathroom that corresponds with their gender identity. Later, he backtracked, saying states such as North Carolina should have the ability to dictate which facilities a trans person can use.

There is one big exception to Trump’s rightward tilt. For the first time in recent memory, Trump, as the Republican nominee for president, proposed a national plan to guarantee paid family leave. (“Wow!” he said when he announced his plan at rallies.)

But the plan doesn’t get you very far if you’re not wealthy, or, in the case of parental leave, if you’re not a woman who has given birth. Trump has proposed giving women six weeks of leave at the same rate as their state’s unemployment benefits. The plan only covers women who have given birth and does not cover fathers at all, nor women who become mothers through adoption or surrogacy. Trump also proposes allowing families to deduct the cost of childcare from their taxes, but economists have criticized the plan as both expensive to taxpayers and of marginal benefit for low-income families.

Wall Street

Trump has a difficult and confusing relationship with Wall Street and it’s not likely to get any better now that he is in the White House.

Stock markets soared the day before the election when the FBI announced it was not going to reopen its investigation into Hillary Clinton’s emails, a move investors bet would boost her chances of election. On Wednesday global markets crashed and the US looked set to follow in the wake of his surprise victory but soon recovered on the back of a conciliatory victory speech from Trump.

Trump has been seen as bad for business. Big banks don’t like his anti-trade policies and the instability his foreign policies might bring. But in some ways Wall Street could find they have a new friend in the White House, as long as they are prepared to suck up to him.

On the campaign trail Trump has consistently railed against Dodd-Frank, the financial rules brought in after the last financial crisis in an attempt to curb Wall Street’s excessive appetite for risk.

“We have to get rid of Dodd-Frank. The banks aren’t loaning money to people that need it … The regulators are running the banks,” he told Fox News last October.

Wall Street would be happy with less regulation but it might not be so happy with Trump’s tax plans. “The hedge fund guys are getting away with murder … They’re paying nothing, and it’s ridiculous,” he told CBS’s Face The Nation last August.

He is proposing to end a tax loophole that allows billionaire hedge fund managers to pay the 20% capital gains tax rate rather than the 39.6% top rate of income tax. He’s also promised to get tough on Wall Street (although confusingly not with regulation).

“I know the people on Wall Street. We’re going to have the greatest negotiators of the world, but at the same time I’m not going to let Wall Street get away with murder. Wall Street has caused tremendous problems for us. We’re going to tax Wall Street,” Trump said at a rally in January.

But his first test may well be the mega-merger of AT&T and Time Warner. Trump has already called the $85bn deal a threat to democracy. If his first move is to signal that the deal is off, Wall Street may worry that businesses will put future deals on hold as long as he’s in the White House.

Climate change

At a pivotal time when greenhouse gas emissions must be drastically shrunk in order to prevent climate breakdown, the world’s largest economy is now headed by a man who believes climate change is a hoax, perhaps perpetrated by the Chinese.

The doomsday moment for a livable climate could well be a step closer with the election of Trump, environmentalists fear.

One of Trump’s first tasks is likely to be withdrawing the US from the Paris climate deal, making it an outlier among the planet’s functioning governments, which have all signed up to the accord. The exit process will take around four years, so the US would be on its own in time for Trump’s second term or a new president’s first.

But the worst of these consequences would unfold after Trump’s presidency, so he could concentrate on his other environmental policies. He’s hinted at scrapping the Environmental Protection Agency, tasking Myron Ebell, a leading climate change denier, to head his EPA transition team.

Trump has also promised to cut all federal climate spending, which would encompass billions of dollars spent on clean energy development and hundreds of millions of dollars in aid to countries at greatest risk from climate change.

Trump has said he will “end the war on coal and the war on miners” in order to reboot the industry, while also expanding drilling for natural gas. He has not explained how these contradictory policies will be achieved, given that the advance of gas has caused the decline in coal, but has insisted upon an “America first” stance on energy.

Gun control

Trump’s win is a tremendous victory for the National Rifle Association, which endorsed him early and has been one of his staunchest allies.

Trump has pledged to roll back gun restrictions to make gun-carrying legal in more places, including on military bases and perhaps in schools. He said he supports a new federal law that would make concealed carry permits issued in one state valid across the country. This legislation, long a policy priority for gun owners, could undermine the current strict local gun restrictions in states like California and New York.

In what was the NRA’s central priority this election, Trump also promised to nominate a staunchly pro-gun supreme court justice to replace Antonin Scalia, which would protect and perhaps even broaden the court’s landmark 2008 Heller decision protecting Americans’ right to own guns for self-defense.

To reduce the toll of gun violence, Trump has argued that law enforcement should be “tougher” and has dubbed himself the “law and order candidate”, a stance that cuts against what had been a growing bipartisan consensus that America’s criminal justice system is too expensive and too punitive.

“We need to get serious about prosecuting violent criminals,” Trump’s second amendment policy briefing reads. “Violent crime in cities like Baltimore, Chicago and many others is out of control. Drug dealers and gang members are given a slap on the wrist and turned loose on the street. This needs to stop.”

Trump has suggested resurrecting a controversial Bush-era federal program, Project Exile, which encouraged US attorneys to use the threat of tougher federal prosecutions for gun crimes to attempt to deter gun violence.

He said in August that he believed Chicago police could put a stop to the city’s spiraling gun violence epidemic “in one week” by “being very much tougher”. The key, he said, was “using tough police tactics, which is OK when people are being killed”.

Trump has also argued that laws that “empower law-abiding gun owners to defend themselves” are “another way to fight crime”.

Trump has been characteristically vague on justice reform. But he has repeatedly pledged support for police officers and law enforcement in the face of public criticism. Candidate Trump has expressed an interest in the continued privatization of prisons, and has criticized President Obama for cutting short the sentences of long-serving nonviolent drug offenders, calling grantees “bad dudes”. He proposed a law mandating the death penalty for anyone convicted of killing a police officer.

Among Trump’s first targets may be rolling back the Obama administration’s unilateral efforts to address mass incarceration. Trump plans to immediately halt the president’s Clemency 2014 initiative, which in 2016 cut short a record number of federal prison sentences. Trump is also likely to undo the executive order signed by the president in May 2015 to curb the transfer of military equipment to police departments.

A veto threat from Trump could thwart any potential for passage of the bipartisan Sentencing Reform and Corrections Act introduced to Congress last year by the Republican senator Chuck Grassley. The bill proposes to reduce mandatory minimum sentencing for non-violent crimes. His election, along with the Republican sweep of both chambers of Congress, seems to squelch any hope of more progressive reform from lawmakers.

A Trump-led Department of Justice and FBI could also spell doom for federal efforts to track police use of force and killings by the police, as Trump has not identified the current lack of data as a priority at any point during the presidential campaign. Trump could also instruct his justice department to change course on its move away from private prisons announced in August.